The congress of Vienna, summoned by the four powers who have done most to defeat Napoleon (Britain, Russia, Prussia, Austria), is an attempt to stabilize the map of Europe after the upheavals caused by more than twenty years of war. All the crowned heads and their representatives are welcome in Vienna, with the result that there is much entertainment and glamorous festivity throughout the winter of 1814-15.

Behind the glitter, orchestrated by Metternich, the hard work of diplomacy goes on. The four great nations intend to make all the decisions themselves, but Talleyrand - representing the newly restored Louis XVIII - ensures that France has an equal place at the table. Her participation in any agreed balance of power will be essential.

Everyone is well aware that a breakdown in the negotiations can easily lead to a renewal of war, in the familiar pattern of recent years. Yet each participant has a vested interest in ensuring that none of the others becomes too strong. The main players are like heavily armed gangsters who nevertheless need to clinch a deal.

Danger lies primarily in Poland and Saxony, the much fought over regions bordered by Russia, Prussia and Austria. Poland has already been dismembered by her neighbours before being partly reconstituted by Napoleon - as a grand duchy which he grants to the king of Saxony. (Saxony remains a French ally longer than anyone else and thus ends up on the losing side.)

Eventually the major powers reach a compromise in Vienna, to the predictable detriment of Poland and of a much reduced Saxony. In most other areas this congress of conservative monarchies restores the pre-Napoleonic status quo. Just as Louis XVIII returns to the French throne, so Naples is restored to the Bourbons, the papal states to the pope, and much of northern Italy to Austria.

Among the more important changes, the larger German states keep their gains from the process of rationalization introduced by Napoleon; Denmark loses Norway to Sweden; and a new kingdom of the Netherlands links the Austrian Netherlands (or Belgium) and the United Provinces, as a barrier to renewed French expansion northwards.

Austria by now has no objection to relinquishing the Austrian Netherlands. But decisions of this kind are old-fashioned diplomacy, conducted between crowned heads and bearing little relation to the wishes or identity of people in the affected areas. Partly for this reason, the newly created kingdom of the Netherlands lasts only fifteen years before splitting apart.

Nevertheless in most respects the negotiators at Vienna succeed in their primary aim of finding a basis for peace. Most of their solutions hold good for several decades. The new Europe of the 19th century is no longer characterized by frequent wars. Instead, each nation is confronted internally by the likelihood of revolution.

Austria and Germany: 1815-1834

It is Austria's hope and intention that the congress of Vienna will restore the Habsburg role within Germany, albeit in a much simplified context. The German states, reduced in number as a result of Napoleon's interference, now consist of thirty-five monarchies of various kinds and four free cities (Hamburg, Bremen, Lübeck and Frankfurt).

They are organized from 1815 into a Deutcher Bund or German Confederation. It is a body with no legislative powers, being merely a diplomatic assembly of rulers or their representatives. Some of the members have only a subsidiary interest in Germany. The British king has a place, as king of Hanover. So does his Danish counterpart, as duke of Holstein.

The assembly meets in Frankfurt and is known as the Bundestag, in succession to the Reichstag of the now defunct Holy Roman empire. Just as the Habsburg emperor presided over the Reichstag, so the Austrian representative is president of this new institution. Its very existence derives from the efforts of Metternich, determined to continue in this new form the hegemony of Austria among the German nations.

By its nature the Confederation can achieve little in the way of change, since it has no authority over individual members except in foreign policy. But it has, as Metternich would wish, a calming effect - or a stultifying one, depending on the point of view.

Good relations within the Confederation depend on an understanding between the two most powerful members, Austria and Prussia, and here the long survival of a trio of colleagues from the congress of Vienna proves a significant factor. The Austrian emperor Francis I lives until 1835; Frederick William III of Prussia dies in 1840; Metternich remains chancellor of Austria until 1848.

All three are equally reluctant to see political change or to introduce liberal measures. Frederick William promises in 1815 a Prussian constitution, but takes no step towards providing one in the next quarter century. However, on the economic front he introduces reforms of profound significance.

The congress of Vienna has given Prussia extensive new lands around the Rhine and the Moselle (partly to protect the new kingdom of the Netherlands from French aggression), but these regions are isolated from the rest of Prussia, being separated by Hanover and other smaller states.

In an effort to bind together his extended kingdom, Frederick William in 1818 turns all his territories into a single customs-free zone. The benefit to trade encourages neighbouring regions to join this Zollverein (customs union), until by 1834 it covers almost the whole of Germany. Austria, with economic links far beyond the German area, is deliberately excluded. So Prussia, as if by the back door, acquires a role of German leadership.

Austria and Italy: 1815-1831

The terms agreed at the congress of Vienna return Italy almost precisely to the situation prevailing before the French intrusion. The king of Sardinia (head of the ancient house of Savoy) recovers his bloc of territory around the western Alps, comprising Savoy, Nice and Piedmont; he acquires also a valuable extension along the coast in the form of Liguria, which previously was the republic of Genoa.

Austrian rule is restored in the large and rich area of northern Italy - from Lombardy, through Parma and down into Tuscany. Here too there is an important addition resulting from the Napoleonic upheavals. Venetia, the province of the republic of Venice, is added to the Austrian empire.

In the central part of the peninsula Rome recovers the papal states. And the whole of southern Italy, previously consisting of the two kingdoms of Naples and Sicily, reverts to its Bourbon monarch Ferdinand. His realm is now merged into a single kingdom of the Two Sicilies, of which he becomes Ferdinand I (having previously been Ferdinand IV of Naples and Ferdinand III of Sicily).

Among these Italian powers Austria is by far the strongest. With Metternich's determination to preserve the royalist status quo in Europe, Austrian armies become the natural policemen on patrol in Italy for any sign of revolution. And there seems to be much going on of a suspicious nature.

In the Italy of the restoration there are many secret societies harbouring radical ideas. Army officers and civil servants, who in many cases have had first-hand experience of the modern French style of administration, are disturbed to find themselves in a reimposed version of the ancien régime.

They crave independence from reactionary rulers. And some are influenced by a vision deriving from Napoleon's hold on the entire peninsula - that of a united Italy, under a single government.

The earliest and best-known among Italy's revolutionary groups are the Carbonari, meaning 'charcoal-burners'. As befits a secret society, their origin is uncertain. When they first emerge from the shadows, in around 1806, the Carbonari are anti-French, opposing in particular the royalist aspect of French rule now that Napoleon is emperor.

After 1815 their quarrel is with the restored royal dynasties in Italy. The first real success of the Carbonari is a revolution in Naples in 1820. It causes Ferdinand to bring in a liberal constitution. But nine months later he invites an Austrian army into his kingdom and returns to absolutist rule.

The pattern of Austrian involvement is soon repeated elsewhere. Secret societies achieve a revolution in Piedmont in 1821, leading to the abdication of the king and a brief constitutional rule until an Austrian army enters Turin and restores the status quo. Similarly, when the revolutionary ferment of 1830 results in unrest in the papal states (in February 1831), the papacy regains control only with the help of Austrian forces.

But the Austrian empire itself is not immune from the spirit of the age, particularly in the regions north and east of Vienna which during the past three centuries have come piecemeal under Habsburg rule.

Austria and ethnic nationalism: 1814-1848

The French revolution and Napoleon's reforms inspire suppressed minorities throughout Europe with the dream of self-determination. This is particularly true in those parts of the Austrian empire where people of non-Germanic origin have a long and proud history of their own.

A sense of increasing unrest is felt in Hungary and Bohemia, and also in smaller regions such as Slovakia and Croatia. Even the German middle classes in Austria feel that change is essential in the stultifying society presided over by Francis I and Metternich, where oppressive bureaucracy is preserved by a network of spies reporting to the secret police.

The ethnic tensions which develop in Hungary and Bohemia are of some complexity. The Germans in these regions of the Habsburg empire take it for granted that they are the ruling community and that German should be the language of government. But the Hungarians, in particular, have a different view of the situation. Enjoying the status of a separate kingdom within the empire (since 1723), they are determined that Magyar traditions shall prevail. The Hungarian diet of 1844 declares that Magyar is to be the official language of the state (see Language and nationalism).

This development in turn outrages another minority group, the Croatians, whose territory lies within the Hungarian kingdom.

The Croatians, as Slavs, are part of the third major strand in the nationalistic aspirations of these regions. Slav demands are more complex than those of the Magyars. They are expressed by geograpically separate groups (including the Czechs and Slovaks) which nevertheless feel a strong sense of shared identity. And the Slavs have a variety of political masters on whom to focus their hatred.

The Croatians and Slovakians are within the Hungarian kingdom. They are therefore anti-Magyar and are willing, for the sake of political alliance, to be pro-German. But the Czechs of Bohemia and Moravia are within Austria and are ruled from Vienna. Their nationalists are uncompromisingly anti-German.

In Bohemia, as in Hungary, nationalism expresses itself through the language and history of the ethnic group. A Bohemian museum is founded in Prague in 1818. A history of Bohemia and Moravia, written by Frantisek Palacky and appearing from 1836, offends the Habsburg censors by identifying the Hussite period as the defining moment of Czech identity.

These nationalist aspirations represent a jockeying for position within the Habsburg empire rather than a bid for full independence. But the issues gain a new intensity in the revolutionary year of 1848.

Revolutions: 1848-1849

The example of the February revolution in Paris prompts a ripple effect in the discontented cities of the Habsburg empire. Vienna is the first to rise, on March 12, and the long-serving chancellor Metternich is the first victim - he is forced to resign on the 13th.

On March 17 the Hungarian diet adopts a liberal consitution which is tantamount to claiming Hungarian independence, leaving a link with Vienna only through the emperor's personal rule as king of Hungary. In normal circumstances this would be a revolutionary act, but in the atmosphere of 1848 it rapidly acquires legitimacy. The emperor (now Ferdinand I) considers it prudent to grant his royal assent, on April 11.

Meanwhile the Slavs see their chance. In April the Croatians declare independence from Hungary and expel Magyars from all civil service posts. In June a pan-Slav congress assembles in Prague with Palacky, the Czech nationalist historian, as president.

The excitement of the occasion is expressed in a demonstration by radical Czech students. The Austrian commander of Prague takes the opportunity to impose martial rule. It is the first of several occasions over the next twelve months in which imperial troops are able to restore order, often because groups with different revolutionary aims fail to assist each other - and even, on occasion, lend their support to the imperial power.

In Vienna, on May 17, the situation is so tense that the emperor Ferdinand I flees for safety to Innsbruck. In August he is persuaded to return to the capital, but on October 6 another uprising delivers the city into the hands of German radicals. This time the emperor escapes to Olomouc in Moravia.

By the end of the month Vienna has been recovered by an imperial army, with the assistance of Croatian revolutionaries hoping to win official support in their own campaign for Slav self-rule. In January 1849 the same alliance, imperial and Croatian, captures the city of Buda where the Hungarian government has been showing aggressive signs of independence, under the leadership of Lajos Kossuth.

By the autumn of 1849 the Habsburg empire is back under control. As in the aftermath of any failed revolutionary period, the reaction is harsh. Executions of radical leaders in Vienna and Buda are followed by a return to the restrictive rule which preceded the revolutions.

There are only two lasting results. The feeble emperor Ferdinand I abdicates in December 1848 in favour of his young nephew, Francis Joseph, whose 68-year reign sees the Austrian empire almost to its end. And the compulsory labour of serfdom, known in these regions as Robot, is at last abolished in the Habsburg empire (the reform by Joseph II in 1789 having been soon reversed by his younger brother Leopold II).

Repression and compromise in Austria-Hungary: 1849-67

In the years after the defeat of Kossuth's independent Hungary in 1849, the kingdom is ruled from Vienna almost as a subject territory. Administration is conducted largely by Germans and in the German language. The Magyars, accustomed to a position of privilege as the ruling majority, are now treated merely on an equal footing with the other ethnic or linguistic groups.

This policy is met by sullen non-cooperation, highly effective in practical matters such as the payment of taxes. By the 1860s the two sides are willing to compromise. In 1865 a committee is appointed to consider the options for a new constitutional framework.

During the negotiations Austria is distracted by the embarrassingly brief Seven Weeks' War of 1866. But the Austrian defeat does not alter the outcome of the talks, the broad outline of which is already evident.

The proposal is for a return to the separation of the Hungarian kingdom from the Austrian empire, similar to the arrangement of 1723 but falling short of the independence achieved in 1848. Foreign affairs and defence are to be conducted jointly on behalf of the two states, with the responsible ministers being alternately Austrian and Hungarian. On all internal matters Hungary is to be independent.

This arrangement becomes known in German as the Ausgleich, meaning literally 'settlement' but usually translated into English as the Compromise. A Hungarian parliament, reestablished in February 1867, accepts the arrangement in May. Francis Joseph, now nearly twenty years into his reign as emperor of Austria, is crowned king of Hungary in June.

His new realm, with its dual entity, is to be known as Austria-Hungary. The arrangement soothes Magyar aspirations, but it severely affronts the Slavs - now more than ever separated as second-class citizens in two states, the Bohemians and Moravians in Austria and the Slovakians and Croatians in Hungary.

France and Prussia: 1859-1866

The Austrian empire has natural enemies in both France and Prussia. This is particularly true in France after Louis Napoleon becomes emperor in 1852 as Napoleon III. He has his own historic reasons for wishing to push the Austrians from north Italy, the region conquered by Napoleon I and lost at the congress of Vienna. He is also interested in encouraging a united Italy and knows that he would gain much credit by liberating Lombardy and Venetia for the purpose.

Similarly Prussia is vying with Austria for leadership of the German states. This struggle is intensified from 1862, when Prussia acquires an aggressive new prime minister in Bismarck.

France is the first to move against Austria, marching into north Italy in 1859. The result, after a short campaign, is Austria's loss of Lombardy to the kingdom of Sardinia.

The quarrel with Prussia develops more slowly into actual war, and is considerably more harmful to Austria's prestige. The immediate crisis begins with disagreement over the administration of the duchies of Schleswig and Holstein. Bismarck heightens the tension in 1866 by marching Prussian troops into Austria's province of Holstein.

Austria, presiding over the German Confederation (a role acquired half a century earlier at the congress of Vienna), proposes that the Confederation as a whole should restrain its belligerent member. Prussia, certain to be outvoted on the issue, responds on 14 June 1866 by declaring the Confederation defunct.

On June 15, when Saxony, Hanover and Hesse-Kassel refuse to give assurances that they will remain neutral, Prussia invades all three states. The war deciding the future shape of Germany has begun. It will be a short one.

Seven Weeks' War: 1866

The speed of Prussia's victory in the war of 1866 against Austria is largely the result of reforms carried out in the Prussian army by Helmut von Moltke. Appointed chief of the general staff in 1857, he appreciates that recent technological developments - in particular railways and telegraphy - transform the nature of war (as the civil war in America has recently shown). Troops can move fast to seize sudden opportunities. Separate armies can remain in communication while fighting a single campaign on an extended front.

This new strategy requires a much larger and more highly trained general staff, responsible for overall planning and the provision of accurate maps and up-to-date intelligence.

Moltke has several years in which to train his staff and develop new battle plans before Prussia has to face an enemy of equal stature - the Austrian empire, in 1866. He also has the advantage that the Prussian army is now fully equipped with the Dreyse breech-loading rifle (introduced from 1848). The Austrian infantry, still loading their muskets by ramming powder and shot down the muzzle, have a much slower rate of fire.

With these advantages, Prussia achieves what can be described as the first blitzkrieg (lightning war). Troops are transported to various points on a front of about 270 miles along the northern border of Bohemia (part of the Austrian empire).

Entering Bohemia at several different places, the invading forces form into a single army to confront the Austrians in a major battle at the village of Sadowa, near Königgrätz, on July 3. The result is inconclusive, but the Prussians are able to push on south to the outskirts of Vienna - where an armistice is agreed on July 22.

Meanwhile other Prussian armies have been winning victories against Hanover in the west and against Bavaria (and other smaller states loyal to the German Confederation) in the southwest. An armistice has been agreed on all fronts by the end of July, bringing the hostilities to an end within seven weeks.

With the treaty signed in Prague, on August 23, Bismarck demonstrates conclusively that the leadership of the German world, exercised for four centuries by Habsburg Austria, has now passed to Hohenzollern Prussia.

The specific point at issue is resolved by Austria ceding all rights in Schleswig-Holstein to Prussia. More important is the article in the treaty where Austria consents to a 'new organization of Germany' from which Austria will be excluded. This is all that Bismarck needs. His king, William I, is eager to annexe part of Austria. But Bismarck prefers a humiliated but intact Austrian empire on his southeastern flank. On this point Bismarck prevails. Prussian policy is clearly to be his policy.

The humiliation of 1866 reduces Austria's role in the affairs of western Europe. Instead attention focuses in coming years on two issues nearer home. One is the difficulty of balancing the demands of the non-German groups (Slavs and Magyars) within Austria-Hungary. The other is the constant Austrian need to keep an eye on the volatile affairs of the Balkan states to the southeast.

Bosnia-Hercegovina, in particular, is the subject of prolonged Austrian involvement from 1878.